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| 2023 Tesla Model Y LR |
Three years ago we brought home a new Tesla Model Y Long Range. This made our home fleet a 2018 Model 3 and a 2023 Model Y; all EV, two Teslas. A couple of months ago, we sold our Model 3. This moved the Model Y from being just the vehicle that we each prefer to drive to our only vehicle. With roughly 24,400 miles on the Y's odometer at the end of year 3, it is time for the annual look back at how the Y has performed, where we have taken it, what software has arrived, and how the battery is holding up.
Miles and Moments on the Road
This year we added just over 7,000 miles. No big outting this year, just typical daily drives with a few regional day trips mixed in. The lack of long trips, also means we didn't Supercharging this year. A long range EV is very convenient when you can take a day trip to the gorge, the mountain, or the beach and make it back home on the same charge.
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| Hauling Home 3 Schip Laurels on an X-Rack |
Tires, Speed, Weather, & Efficiency
The original Continental all-season tires and the Michelin winter set continue their seasonal rotation. Efficiency numbers stay in the same ballpark we saw last year: the all-seasons run more efficiently than the winter tires. For us, summer driving is generally 17% more efficient than winter trips (tires, temps, and weather all contribute to this range impact). Both sets of tires still have useful tread life left for another season or two of mixed Pacific NW weather.
Speaking of weather, in the chart below you can see a graph of efficiency vs temp. Anywhere from 65F to 90F is where the range is highest. The uptick at 100-105F does not have enough data to be considered valid.
Below you can see the next chart of efficiency vs speed. Twenty to twenty five MPH is the sweet spot but the efficiency doesn't drop off too quickly, and is still above 74% even at 70MPH. I don't hypermile like I did in my short range EVs of yesteryear.
Firmware, Features, and FSD Progress
We began the third year on software version 2025.26.4. We received 21 updates throughout the year and finished on build 2026.20.6.11 that included FSD Supervised v14.3.9. The steady stream of updates continues to bring small quality-of-life improvements, better camera views, refined collision warnings, and incremental FSD gains.
One of the best improvements arrived in April 2026 when dashcam retention expanded from 1 hour to 24 hours (assuming you have a large enough drive). If you are ever involved in a collision, you might not be able to grab the video quickly. This gives you much more of a chance to retrieve video that could help you prove the cause of the incident. Now you can also permanently save any clip from the previous day via the Dashcam Viewer.
During the third year, FSD Supervised has moved from v13 to v14 and through several v14 builds. Unlike v9 that drove like a 15 year old, v14 is more confident in ordinary traffic. My intervention rate continues to decline. The new parking lot features were a welcome addition, it now remembers my preferred parking area. Lately, my interventions have been related to left turns onto a multi-lane road. FSD will often "swing wide" also called "widening the turn" or "drifting out." This is a common human driver error and I suspect the training data has too many occurrences. Depending on local jurisdiction, law enforcement may ticket this specific mistake as an improper turn, failure to maintain a single lane, or an unsafe lane change. I'll keep intervening every time it tries to earn a traffic ticket and eventually, the training set will be culled of this poor behavior.
Battery Health After Three Years
Lithium-ion battery packs show heavy initial capacity fade in their first year as the Solid Electrolyte Interphase (SEI) layer (a protective chemical film formed on the anode surface from decomposed electrolyte components) matures, followed by a prolonged, gradual transition into steady-state degradation over the next few years.
The chemical growth of the SEI layer is governed by diffusion-controlled kinetics, meaning it follows a square-root-of-time model. Because the protective film is thinnest during the first two years, lithium ions diffuse through it relatively easily, causing faster early-stage consumption of lithium inventory and associated degradation.
By year 4, that layer has thickened. Ions now have to travel much further through a dense, established passivation barrier, causing the rate of new SEI growth to slow down to a microscopic crawl. For our Y, years 4 and 5 could see a relatively flat degradation curve, with capacity loss under 1% per year.
At the end of year three the measured degradation stands below 10%. That brings the estimated remaining capacity to 76.9 kWh (with 72.9 kWh usable), resulting in an effective EPA-rated range of roughly 300 miles, compared to the 330 miles that we started with 3 years ago. The Long Range configuration still leaves comfortable margin for the trips we take, including winter conditions with a full load and roof rack.
We continue to keep the daily charge target in the middle of the pack rather than topping it off every night. That habit, combined with mostly Level 2 home charging, appears to be treating the cells reasonably well. The warranty still covers the pack well beyond our current mileage and age, so there is no practical concern.
| Item | Year 1 | Year 2 | Year 3 |
|---|---|---|---|
| Approximate Miles Added | ~9,000 | ~8,000 | ~7,000 |
| Cumulative Odometer | ~9,000 | ~17,000 | 24,000 |
| Supercharger Sessions | 1 | 4 | 0 |
| Reported Battery Degradation | 1.9% | 5.5% | 1.7% |
Looking at the degradation line it interesting. The year we Supercharged the most (year 2) is also the year we had the most degradation. However, these events are not likely causally related. Our charging habit of keeping the battery in a tight 40% to 62% charge window most days with only an occasional 100% calibration charge can starves the BMS for data, causing estimation drift. This combined with calendar aging and normal wear likely created a temporary reporting anomaly with degradation that actually occured in year 1 not showing up until later.
Steady Ownership, Steady Progress
Three years in, the Model Y continues to do exactly what we asked of it. It handles the daily errands, the occasional mountain or coast run, and the software updates that keep arriving with new features and improvements. Battery capacity has now settled into a slower decline after the expected early drop. Range remains more than adequate. Charging is almost entirely an at home affair.
The Y has simply become part of the household routine. That quiet reliability is the real story after three years. The one and only Tesla service visit our Y has had was during year 2 when Tesla upgraded the in-cabin mmwave sensor and that was done by mobile service while the vehicle sat in our driveway. We will keep tracking the numbers and share the Year 4 update when the odometer and the calendar line up again. In the meantime the Model Y keeps moving us toward a future free from fossil fuels, one practical mile at a time.
You can read the Year 1 report here and the Year 2 report here.
If you are considering a Model Y or another Tesla, my referral link is: https://ts.la/patrick7819.
If you want to track your Tesla's detailed battery performance and trip tracking, the you can use my TeslaFi referral code.











